1. Field of the Invention
The present invention relates generally to fitness apparatuses, and more particularly to an exercise wheel.
2. Description of the Related Art
As shown in FIG. 1, a conventional exercise wheel includes a hollow shaft 81 provided with a slot 82 extending from one end thereof to a midpoint thereof; a volute spring 83 provided with a locating piece 831 confined in the slot 82 of the shaft 81; and two rollers 84 provided at the center thereof with a round hole 85 dimensioned to fit over both ends of the shaft 81. The two rollers 84 are provided with a hollow guide pillar 86 for fastening a bolt 87. One guide pillar 86′ is shorter than the other guide pillar 86 for engaging the locating piece 832 of the volute spring 83. In operation, both hands of an exerciser hold two ends of the shaft 81 to roll the roller on a surface in a reciprocating manner. As the wheel is rolled forward, the volute spring 83 is compressed. When the wheel is rolled backward, the wheel is provided by the compressed volute spring 83 with a recovery spring force.
However, the conventional exercise wheel described above includes the following drawbacks in need of improvement.
1. It has only one wheel by which the exerciser can not keep his or her body in balance with ease while moving the body forward or backward, such that it is not convenient for the exerciser to operate the exercise wheel.
2. While the exerciser operates the exercise wheel, the exerciser's body is subject to sideward turnover. If the sideward turnover happens, the exercise may feel nervous or exert overgreat strength to get strain.
Some improved inventions were proposed and had been patented, like U.S. Pat. No. 6,254,518, for the aforesaid conventional exercise wheel. However, it is still not preferable for the exerciser to steer the forward or backward movement of those improved exercise wheels because they did not provide any additional assistance for the exerciser to control their moving directions. For example, the aforesaid '518 patent though provides a front wheel for the exerciser to control the moving direction of the exercise wheel, but an elastic device keeps applying the resilience to interfere the moving direction of the exercise wheel. Besides, it is not limited to change the moving direction of the front wheel. If the moving direction of the exercise wheel is changed by the exerciser involuntarily, the exerciser may get hurt.